package day01;

import java.util.Scanner;

public class demo4 {
    public static void main(String[] args) {
        Scanner grade=new Scanner(System.in);
        int score;
        System.out.println("请输入一个成绩");
        score=grade.nextInt();
        if(score<0 || score>100){
            System.out.println("成绩无效");
        }else{
            if (score>=90){
                System.out.println("A");
            }else if(score>=80){
                System.out.println("B");
            }else if(score>=70){
                System.out.println("C");
            }else if(score>=60){
                System.out.println("D");
            }else{
                System.out.println("e");
            }


        }
    }
}
